[time-nuts] is my Oncore UT+ dead or live?
How does one tell a dead Oncore UT+ from a live one? Sounds like a silly question but the user manual says they produce no output until you send it some commands. I connect an older Germin GPS to the same cable and a flood of NMEA messages appears in a terminal window. I'm running Linus and just using cat to send ad receive data. -- = Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] is my Oncore UT+ dead or live?
How does one tell a dead Oncore UT+ from a live one? Sounds like a silly question but the user manual says they produce no output until you send it some commands. I connect an older Germin GPS to the same cable and a flood of NMEA messages appears in a terminal window. I'm running Linus and just using cat to send ad receive data. NMEA devices are generally setup that way. Oncores also support a binary mode. You might try ntpd. Driver 30 talks to Oncores. It puts stuff into clockstats and/or you can run it in debugging mode to get lots and lots of console printout. The driver30 web page says it defaults to doing a site survey. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] is my Oncore UT+ dead or live?
Hi Chris, use the TAC32 software to initialize the gps board probably when you power up it comes into binary mode, not NMEA mode Rgds Ernie. -Original Message- From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sat, Jan 8, 2011 10:41 am Subject: [time-nuts] is my Oncore UT+ dead or live? How does one tell a dead Oncore UT+ from a live one? Sounds like a illy question but the user manual says they produce no output until ou send it some commands. I connect an older Germin GPS to the same cable and a flood of NMEA essages appears in a terminal window. I'm running Linus and just sing cat to send ad receive data. -- hris Albertson edondo Beach, California ___ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] T-Bolts object to being dropped.....
Hello, Time Nutters Last week I was rearranging gear on a shelf over my workbench. I managed to knock my T-bolt off the shelf and onto the top of the workbench, about a 20-inch fall. After I finished calling myself a $...@$%*#@ idiot, I hooked it back up and, just as I feared, there was a BAD OSCILLATOR warning and something about an OSCILLATOR AGE warning. There was no oscillator output. ggg Taking it apart to see what I could find, I noted that the OCXO WAS running, but apparently so far off that no lock occurred. Thinking I had nothing to lose, I considered removing the access screw over the oscillator tweaking adjustment and seeing if I could resurrect it, but decided I had done enough damage for the day and went back into the house whimpering over the demise of my T-bolt. However, the next day, it had recovered all on its own, at least enough that there was normal output, although the steering voltage was nearly at its limit. Over the following week, it slowly recovered and appears now to be back to normal with all parameters right where they used to be. No permanent damage seems to have been done Mike Baker ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] T-Bolts object to being dropped.....
I wonder what could have caused this? Other than the xtals, what could be shock sensitive I wonder! At 08-01-2011, you wrote: Hello, Time Nutters Last week I was rearranging gear on a shelf over my workbench. I managed to knock my T-bolt off the shelf and onto the top of the workbench, about a 20-inch fall. After I finished calling myself a $...@$%*#@ idiot, I hooked it back up and, just as I feared, there was a BAD OSCILLATOR warning and something about an OSCILLATOR AGE warning. There was no oscillator output. ggg Taking it apart to see what I could find, I noted that the OCXO WAS running, but apparently so far off that no lock occurred. Thinking I had nothing to lose, I considered removing the access screw over the oscillator tweaking adjustment and seeing if I could resurrect it, but decided I had done enough damage for the day and went back into the house whimpering over the demise of my T-bolt. However, the next day, it had recovered all on its own, at least enough that there was normal output, although the steering voltage was nearly at its limit. Over the following week, it slowly recovered and appears now to be back to normal with all parameters right where they used to be. No permanent damage seems to have been done Mike Baker -- Raj, VU2ZAP Bangalore, India. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] T-Bolts object to being dropped.....
My first order guess would be something like the crystal support wires annealing after the shock. Second would be contaminants knocked loose onto the crystal changing it's mass, and thus operating frequency and boiling back off with some operating time (or maybe just standby time.) Third would be that the crystal slid a fraction of a thou or so in it's mounts and needed to seal the connection with a little operation. All gross speculation, of course. On 1/8/2011 8:21 AM, Raj wrote: I wonder what could have caused this? Other than the xtals, what could be shock sensitive I wonder! At 08-01-2011, you wrote: Hello, Time Nutters Last week I was rearranging gear on a shelf over my workbench. I managed to knock my T-bolt off the shelf and onto the top of the workbench, about a 20-inch fall. After I finished calling myself a $...@$%*#@ idiot, I hooked it back up and, just as I feared, there was a BAD OSCILLATOR warning and something about an OSCILLATOR AGE warning. There was no oscillator output. ggg Taking it apart to see what I could find, I noted that the OCXO WAS running, but apparently so far off that no lock occurred. Thinking I had nothing to lose, I considered removing the access screw over the oscillator tweaking adjustment and seeing if I could resurrect it, but decided I had done enough damage for the day and went back into the house whimpering over the demise of my T-bolt. However, the next day, it had recovered all on its own, at least enough that there was normal output, although the steering voltage was nearly at its limit. Over the following week, it slowly recovered and appears now to be back to normal with all parameters right where they used to be. No permanent damage seems to have been done Mike Baker -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Simulating LORAN-A GRI Timing Generator
Loran c was complicated by the fact that there were phase reversals in the patterns that had to be emulated it doubled the size of the code. But to answer your question John its all done in simple readable basic language. Think of it as a endless loop pattern. The real trick is using a good reference. I think Magnus said 10 KC. What you do is count the 10 KC reference. Using a Parallax SXB chip that can run all the way up to 80 Mhz. The code runs so fast that 99.9% of the time the micro is just waiting and counting edges. I like to create dumb simple stupid, reliable as heck programs like that. The Loran C sim allows the Austrons to compare to their limit of 1 e -13. There is a bit more cleverness in the C simulator external to the program. I thought there were different frequencies at about 1.8 Mhz. I remember the gone-ometer (I still think thats a disease sailors can get), green crt black box about 2 ft tall. If you really wanted to do a location you might need 2 or 3 chips at different GRIs and phases. But at $3.56 not a really big deal. Lastly there must be some overall sync relationship between the chains that has to be maintained I might guess. Oddly enough I emailed the group several times at the ship and never received a response. Figured they were all set. Regards Paul. On Sat, Jan 8, 2011 at 1:27 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 08/01/11 06:54, Magnus Danielson wrote: John, On 08/01/11 05:04, J. Forster wrote: Magnus, See my post of a few minutes ago. The GRI and Delay counters need to be 5 decimal digits. My current thinking is manual entry of the numbers via BCD coded thumbwheel switches. If you only need a static location that will be fine. Naturally you tune it up to the ships current (final?) position. Good exercise for the visitors. :) LORAN-A has 24 possible GRIs; in three blocks of 33 PPS; 25 PPS; and 20 PPS. It also has 4 RF frequencies. I did a fashinating read-up here: http://www.jproc.ca/hyperbolic/loran_a.html GRI is a LORAN-C term if I get it correctly, where as PRR is used together with frequency indication in LORAN-A. Pondering some more on this, doing some calculations (spread-sheets) the actual scheme emerge... the range of 0 to 7 is not selected by accident. The base pulse repetition rate is 30 ms, 40 ms and 50 ms. The pulse repetition rate modifiers modifies the repetition rate by -100 us per step. It would only take two (or possibly three) wheels to select PRR. This explains the high rate starts with 33 3/9... it also makes the receiver design easier to understand. So a 10 kHz source would suffice for PRR settings. A phantastron divider from a 100 kHz standard should do it in those days technology, if not a 10 kHz standard was used directly. Only the delayed pulse would need the full set of thumb-wheels. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] T-Bolts object to being dropped.....
I might guess these effects. But more important is the efc voltage now at one end or the other. Essentially running out of control range but still working??? Regards Paul. On Sat, Jan 8, 2011 at 9:31 AM, Oz-in-DFW li...@ozindfw.net wrote: My first order guess would be something like the crystal support wires annealing after the shock. Second would be contaminants knocked loose onto the crystal changing it's mass, and thus operating frequency and boiling back off with some operating time (or maybe just standby time.) Third would be that the crystal slid a fraction of a thou or so in it's mounts and needed to seal the connection with a little operation. All gross speculation, of course. On 1/8/2011 8:21 AM, Raj wrote: I wonder what could have caused this? Other than the xtals, what could be shock sensitive I wonder! At 08-01-2011, you wrote: Hello, Time Nutters Last week I was rearranging gear on a shelf over my workbench. I managed to knock my T-bolt off the shelf and onto the top of the workbench, about a 20-inch fall. After I finished calling myself a $...@$%*#@ idiot, I hooked it back up and, just as I feared, there was a BAD OSCILLATOR warning and something about an OSCILLATOR AGE warning. There was no oscillator output. ggg Taking it apart to see what I could find, I noted that the OCXO WAS running, but apparently so far off that no lock occurred. Thinking I had nothing to lose, I considered removing the access screw over the oscillator tweaking adjustment and seeing if I could resurrect it, but decided I had done enough damage for the day and went back into the house whimpering over the demise of my T-bolt. However, the next day, it had recovered all on its own, at least enough that there was normal output, although the steering voltage was nearly at its limit. Over the following week, it slowly recovered and appears now to be back to normal with all parameters right where they used to be. No permanent damage seems to have been done Mike Baker -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Simulating LORAN-A GRI Timing Generator
John, On 08/01/11 05:04, J. Forster wrote: Magnus, See my post of a few minutes ago. The GRI and Delay counters need to be 5 decimal digits. My current thinking is manual entry of the numbers via BCD coded thumbwheel switches. If you only need a static location that will be fine. Naturally you tune it up to the ships current (final?) position. Good exercise for the visitors. :) True, and that's the plan. The TDs would vary very slowly when the ship is underway anyway. Not something a visitor would really notice. Roughly, the TDs change a microsecond for every 1/5 mile. Clearly, if the TDs were settable from an external 'puter, a manovercould be simulated, but visitors don't get to twiddle knobs (they steal them), so a static display is probably best. LORAN-A has 24 possible GRIs; in three blocks of 33 PPS; 25 PPS; and 20 PPS. It also has 4 RF frequencies. I did a fashinating read-up here: http://www.jproc.ca/hyperbolic/loran_a.html Yes, Jerry's site is very good on many things like LORAN and radios and crypto. GRI is a LORAN-C term if I get it correctly, where as PRR is used together with frequency indication in LORAN-A. You got me! Yes. GRI = 1/PRF. I prefer to deal with microseconds than 1/9 CPS. Currently I plan only one Slave, but a second would be an easy addition. Indeed. Considering the chain that used to be there, you could allow for two chains to be setup on the same frequency (1H chains). Cheers, Magnus Right. Thanks, -John ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] [Fwd: Re: Simulating LORAN-A GRI Timing Generator]
Pondering some more on this, doing some calculations (spread-sheets) the actual scheme emerge... the range of 0 to 7 is not selected by accident. The base pulse repetition rate is 30 ms, 40 ms and 50 ms. The pulse repetition rate modifiers modifies the repetition rate by -100 us per step. It would only take two (or possibly three) wheels to select PRR. This explains the high rate starts with 33 3/9... it also makes the receiver design easier to understand. Very interesting observation! I did the calculation using Excel (attached) but missed the 100 uS increments., I was blinded by modern precision. Since the LORAN Indicator has sync circuits, your observation is a nice simplification. Thank you. So a 10 kHz source would suffice for PRR settings. A phantastron divider from a 100 kHz standard should do it in those days technology, if not a 10 kHz standard was used directly. Only the delayed pulse would need the full set of thumb-wheels. Cheers, Magnus LORAN-A GRIs.xls Description: MS-Excel spreadsheet ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Simulating LORAN-A GRI Timing Generator
Loran c was complicated by the fact that there were phase reversals in the patterns that had to be emulated it doubled the size of the code. But to answer your question John its all done in simple readable basic language. Think of it as a endless loop pattern. The real trick is using a good reference. I think Magnus said 10 KC. What you do is count the 10 KC reference. Using a Parallax SXB chip that can run all the way up to 80 Mhz. The code runs so fast that 99.9% of the time the micro is just waiting and counting edges. OK. Thanks. You talk to the uP with a dumb terminal program? I like to create dumb simple stupid, reliable as heck programs like that. The Loran C sim allows the Austrons to compare to their limit of 1 e -13. There is a bit more cleverness in the C simulator external to the program. I thought there were different frequencies at about 1.8 Mhz. There are 3 between 1.8 and 2.0 MHz, one higher that was mostly unused. I remember the gone-ometer (I still think thats a disease sailors can get), green crt black box about 2 ft tall. That's for a DF loop, no? Was that used on the LORAN receiver? If so, that's news to me. The crossed roughly 4' loops were common on ships, but I didn't think they were LORAN antennas. If you really wanted to do a location you might need 2 or 3 chips at different GRIs and phases. But at $3.56 not a really big deal. Lastly there must be some overall sync relationship between the chains that has to be maintained I might guess. I'm not sure about inter-chain sync, but IMO it does not matter much. Oddly enough I emailed the group several times at the ship and never received a response. Figured they were all set. Regards Paul. If you're interested, I can make sure you talk to the right person. Best, -John === ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] [Fwd: Re: Simulating LORAN-A GRI Timing Generator]
Well I might be crazy but this seems perhaps easy since reading the link provided. The slaves listened to the master and provided a pulse. So for at least a rate 1 chip could do the job. Essentially the master pulse and then a delay to the slave position. If I am interpreting the info correct the pulse were 40 us wide and made of the carrier frequency like 1.95 MC. A solution would need 2 or 3 of these widgets to give the 3 lines. But do not need to be synchronized because the value of the informations contained within the delay relationship between the master and slave. Regards Paul On Sat, Jan 8, 2011 at 10:08 AM, J. Forster j...@quik.com wrote: Pondering some more on this, doing some calculations (spread-sheets) the actual scheme emerge... the range of 0 to 7 is not selected by accident. The base pulse repetition rate is 30 ms, 40 ms and 50 ms. The pulse repetition rate modifiers modifies the repetition rate by -100 us per step. It would only take two (or possibly three) wheels to select PRR. This explains the high rate starts with 33 3/9... it also makes the receiver design easier to understand. Very interesting observation! I did the calculation using Excel (attached) but missed the 100 uS increments., I was blinded by modern precision. Since the LORAN Indicator has sync circuits, your observation is a nice simplification. Thank you. So a 10 kHz source would suffice for PRR settings. A phantastron divider from a 100 kHz standard should do it in those days technology, if not a 10 kHz standard was used directly. Only the delayed pulse would need the full set of thumb-wheels. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Simulating LORAN-A GRI Timing Generator
The goniometer that I remember was to allow a controlled phase change for measurments. It was inside the rcvr. On Sat, Jan 8, 2011 at 10:28 AM, J. Forster j...@quik.com wrote: Loran c was complicated by the fact that there were phase reversals in the patterns that had to be emulated it doubled the size of the code. But to answer your question John its all done in simple readable basic language. Think of it as a endless loop pattern. The real trick is using a good reference. I think Magnus said 10 KC. What you do is count the 10 KC reference. Using a Parallax SXB chip that can run all the way up to 80 Mhz. The code runs so fast that 99.9% of the time the micro is just waiting and counting edges. OK. Thanks. You talk to the uP with a dumb terminal program? I like to create dumb simple stupid, reliable as heck programs like that. The Loran C sim allows the Austrons to compare to their limit of 1 e -13. There is a bit more cleverness in the C simulator external to the program. I thought there were different frequencies at about 1.8 Mhz. There are 3 between 1.8 and 2.0 MHz, one higher that was mostly unused. I remember the gone-ometer (I still think thats a disease sailors can get), green crt black box about 2 ft tall. That's for a DF loop, no? Was that used on the LORAN receiver? If so, that's news to me. The crossed roughly 4' loops were common on ships, but I didn't think they were LORAN antennas. If you really wanted to do a location you might need 2 or 3 chips at different GRIs and phases. But at $3.56 not a really big deal. Lastly there must be some overall sync relationship between the chains that has to be maintained I might guess. I'm not sure about inter-chain sync, but IMO it does not matter much. Oddly enough I emailed the group several times at the ship and never received a response. Figured they were all set. Regards Paul. If you're interested, I can make sure you talk to the right person. Best, -John === ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] [Fwd: Re: Simulating LORAN-A GRI Timing Generator]
John, On 08/01/11 16:08, J. Forster wrote: Pondering some more on this, doing some calculations (spread-sheets) the actual scheme emerge... the range of 0 to 7 is not selected by accident. I had essentially the same spread sheet... However, how would you be able to achieve simplicity of design by being true to the PRI/PRR given or to what seems like reasonable counter based solution. Notice that the ARN-4 has a Crystal phasing control to adjust the crystal frequency of the receiver so that the receiver will align up to the actual rate of the master station. I think the PRI/PRR given is a presentation simplification rather than true numbers. Considering that absolute frequency was not a requirement, the repetition rate of the master needs to be sufficiently stable for distinction of station and the receiver to make stable reading, in presence of other stations. That LORAN-C uses GRI indications with repetition rate in microseconds, and fairly even such numbers as well, is another hint. Thus, I view the PRI/PRR ratios as approximations at best, a matter of presentation rather than actual nominal rates. Cheers, Magnus lorana.xls Description: MS-Excel spreadsheet ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Simulating LORAN-A GRI Timing Generator
Paul, I see none on the prints. It may have been used on later receiver designs. Thanks, -John = The goniometer that I remember was to allow a controlled phase change for measurments. It was inside the rcvr. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] [Fwd: Re: Simulating LORAN-A GRI Timing Generator]
So if I read the excel correctly you only actually need 1 system. Say H0 is the master then the delays for H1-X is how far away from the master the pulse would be. More importantly you would only need 2 other of the Hs to create a navigational fix. Is this a correct interpretation? Have to go dig out of the snow. On Sat, Jan 8, 2011 at 10:35 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: John, On 08/01/11 16:08, J. Forster wrote: Pondering some more on this, doing some calculations (spread-sheets) the actual scheme emerge... the range of 0 to 7 is not selected by accident. I had essentially the same spread sheet... However, how would you be able to achieve simplicity of design by being true to the PRI/PRR given or to what seems like reasonable counter based solution. Notice that the ARN-4 has a Crystal phasing control to adjust the crystal frequency of the receiver so that the receiver will align up to the actual rate of the master station. I think the PRI/PRR given is a presentation simplification rather than true numbers. Considering that absolute frequency was not a requirement, the repetition rate of the master needs to be sufficiently stable for distinction of station and the receiver to make stable reading, in presence of other stations. That LORAN-C uses GRI indications with repetition rate in microseconds, and fairly even such numbers as well, is another hint. Thus, I view the PRI/PRR ratios as approximations at best, a matter of presentation rather than actual nominal rates. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] [Fwd: Re: Simulating LORAN-A GRI Timing Generator]
John, On 08/01/11 16:08, J. Forster wrote: Pondering some more on this, doing some calculations (spread-sheets) the actual scheme emerge... the range of 0 to 7 is not selected by accident. I had essentially the same spread sheet... However, how would you be able to achieve simplicity of design by being true to the PRI/PRR given or to what seems like reasonable counter based solution. I think the PRR of the transmitters was crystal controlled. I'm gettring a Test Set with a 1.81818 KHz crystal in it... yes 1818.18 Hz!!... that simulates a transmitter. The receive set seems to be free-running, crystal referenced. I don't think it automatically locks up on the Master pulse. I see no indication that the received signal connects to any timing stuff. Notice that the ARN-4 has a Crystal phasing control to adjust the crystal frequency of the receiver so that the receiver will align up to the actual rate of the master station. The DAS-1 has a left-off-right control on the master crystal. It seems like thye operator manually saligns the Master pulse, and the drift rate is low enough to allow TD measurement. I think the PRI/PRR given is a presentation simplification rather than true numbers. Certainly possible, althyough 100 uS increments is pretty simple too. Considering that absolute frequency was not a requirement, the repetition rate of the master needs to be sufficiently stable for distinction of station and the receiver to make stable reading, in presence of other stations. That LORAN-C uses GRI indications with repetition rate in microseconds, and fairly even such numbers as well, is another hint. Thus, I view the PRI/PRR ratios as approximations at best, a matter of presentation rather than actual nominal rates. Cheers, Magnus I don't know. It's certainly an interesting possibility. Thanks, -John = ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] [Fwd: Re: Simulating LORAN-A GRI Timing Generator]
My belief is, if you were looking at the H0 Master, and H0 has two Slaves, the two TDs (one to each slave) is sufficient to give you a position fix. LORAN-A stations were closer together than LORAN-C (maybe 600 mi). Nothing I have read to date indicated there were more than 2 Slaves per Master. Since it seems impossible to distinguish between the Slaves, based on their signals, there might be two apparently valid position solutions. -John == So if I read the excel correctly you only actually need 1 system. Say H0 is the master then the delays for H1-X is how far away from the master the pulse would be. More importantly you would only need 2 other of the Hs to create a navigational fix. Is this a correct interpretation? Have to go dig out of the snow. On Sat, Jan 8, 2011 at 10:35 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: John, On 08/01/11 16:08, J. Forster wrote: Pondering some more on this, doing some calculations (spread-sheets) the actual scheme emerge... the range of 0 to 7 is not selected by accident. I had essentially the same spread sheet... However, how would you be able to achieve simplicity of design by being true to the PRI/PRR given or to what seems like reasonable counter based solution. Notice that the ARN-4 has a Crystal phasing control to adjust the crystal frequency of the receiver so that the receiver will align up to the actual rate of the master station. I think the PRI/PRR given is a presentation simplification rather than true numbers. Considering that absolute frequency was not a requirement, the repetition rate of the master needs to be sufficiently stable for distinction of station and the receiver to make stable reading, in presence of other stations. That LORAN-C uses GRI indications with repetition rate in microseconds, and fairly even such numbers as well, is another hint. Thus, I view the PRI/PRR ratios as approximations at best, a matter of presentation rather than actual nominal rates. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Simulating LORAN-A GRI Timing Generator
John, Quoting J. Forster j...@quik.com: The GRI and Delay counters need to be 5 decimal digits. My current thinking is manual entry of the numbers via BCD coded thumbwheel switches. More than thirty years ago, I built a Rate Generator for LORAN-C excatly according to the above principle. It is still wandering at my junk box and is a three digit preset counter (3XSN7490) a quad input decoding gate (SN7420) and the thumbwheel switches. Using more or less the same principle there is also a six digit delay resolving one microsecond. They are very ancient designs but they work pretty well. Best regards Antonio CT1TE ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Simulating LORAN-A GRI Timing Generator
That's just about what I want to do. Best, -John John, Quoting J. Forster j...@quik.com: The GRI and Delay counters need to be 5 decimal digits. My current thinking is manual entry of the numbers via BCD coded thumbwheel switches. More than thirty years ago, I built a Rate Generator for LORAN-C excatly according to the above principle. It is still wandering at my junk box and is a three digit preset counter (3XSN7490) a quad input decoding gate (SN7420) and the thumbwheel switches. Using more or less the same principle there is also a six digit delay resolving one microsecond. They are very ancient designs but they work pretty well. Best regards Antonio CT1TE ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Anybody have a GPS antenna for sale?
Hello, folks. I have a Truetime XL-DC GPS receiver, which I am trying to get tested. I picked it up sight unseen, and plan to sell it once I can verify its condition. I powered it up today and it seems to be ok at the most basic level (screen works, responds to keypad, etc), but I don't have a suitable GPS antenna for it. Does anybody in listland have an antenna for sale? The unit has a BNC connector for the antenna. The manual I found indicates it needs a 12V compatible antenna with a gain at the receiver connector of 20 to 36dB. Thanks. -Pete ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Anybody have a GPS antenna for sale?
On Sat, Jan 8, 2011 at 4:12 PM, Peter Loron pet...@standingwave.org wrote: ... The manual I found indicates it needs a 12V compatible antenna with a gain at the receiver connector of 20 to 36dB. Most GPS antenna are 5V. I did just notice a few 12V symetricon units on eBay. -- = Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Anybody have a GPS antenna for sale?
The HAG-240 is 5 to 12v. http://www.hankookantennausa.com/products/gps/gps_019.htm Also 37dB. I wiped out the shelf (4 units), but you can call to see if they have more. http://www.excesssolutions.com/ They looked new to me. $15 for the antenna. $2 for the pipe to hold it. -Original Message- From: Chris Albertson albertson.ch...@gmail.com Sender: time-nuts-boun...@febo.com Date: Sat, 8 Jan 2011 16:29:40 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Anybody have a GPS antenna for sale? On Sat, Jan 8, 2011 at 4:12 PM, Peter Loron pet...@standingwave.org wrote: ... The manual I found indicates it needs a 12V compatible antenna with a gain at the receiver connector of 20 to 36dB. Most GPS antenna are 5V. I did just notice a few 12V symetricon units on eBay. -- = Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] RS XSRM Rubidium
Hi! My RS XSRM Rubidium is having problems. It behaves as there is no light from the lamp, and I can't see any light from it, but I let it warm up again. The manual doesn't give clear indication on how one should observe light, but it seems like there is three locations where some light might be observed if there where any. The lamp assembly do have a 100 MHz resonance going and the assembly do get hot. I need to check the temperature thought. Spare Rubidium lamps seems to be a bit hard to get by. Having asked RS about it I have not been given any indication of availability. RS has designed the unit such that the lamp can be switched while the rest of the unit remains hot. They should have included a small supply of lamps too... I assume that the light is visible, I seem to recall it and I am just too lazy to check the colour right now. If anyone has experience in the XSRM or similar (HP5065A for instance) beasts, please let me know. It would be greatly apprechiated if assistance would let it could go into operational state again. The resonator package is certainly not miniatyrized. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] RS XSRM Rubidium
Lamp is orange purple On Sat, Jan 8, 2011 at 9:56 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Hi! My RS XSRM Rubidium is having problems. It behaves as there is no light from the lamp, and I can't see any light from it, but I let it warm up again. The manual doesn't give clear indication on how one should observe light, but it seems like there is three locations where some light might be observed if there where any. The lamp assembly do have a 100 MHz resonance going and the assembly do get hot. I need to check the temperature thought. Spare Rubidium lamps seems to be a bit hard to get by. Having asked RS about it I have not been given any indication of availability. RS has designed the unit such that the lamp can be switched while the rest of the unit remains hot. They should have included a small supply of lamps too... I assume that the light is visible, I seem to recall it and I am just too lazy to check the colour right now. If anyone has experience in the XSRM or similar (HP5065A for instance) beasts, please let me know. It would be greatly apprechiated if assistance would let it could go into operational state again. The resonator package is certainly not miniatyrized. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Interesting ware of the month. ..
... over at Bunnie Huangs blog: http://www.bunniestudios.com/blog/ Anyone recognize it? It almost has to be a timing receiver of some kind. -- john, KE5FX ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Interesting ware of the month. ..
After looking, and reading some of the other replies, I'm not so sure. That's an awful lot of DSPs and FPGAs for a timing receiver, and the silver square (Y1) in the upper left looks like an OCXO rather than a GPS receiver. Neat site, though. I'm going to bookmark it and see what kind of bizarre hardware gets thrown up for the next ID this thing run. Keep on tickin'... *** REPLY SEPARATOR *** On 08-Jan-11 at 21:36 John Miles wrote: ... over at Bunnie Huangs blog: http://www.bunniestudios.com/blog/ Anyone recognize it? It almost has to be a timing receiver of some kind. -- john, KE5FX ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __ Information from ESET NOD32 Antivirus, version of virus signature database 5770 (20110108) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com -=-=-=-=-=-=-=-=-=-=-=- Bruce Lane, Owner Head Hardware Heavy, Blue Feather Technologies -- http://www.bluefeathertech.com kyrrin (at) bluefeathertech do/t c=o=m Quid Malmborg in Plano... ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
